Last week, the United States Senate had a landmark moment in the fight against global warming when 54 senators came down on the side of tackling this issue now.

While the floor debate on the Climate Security Act was ultimately cut short by a Republican filibuster, our strong vote proves that we are moving in the right direction.

When a comprehensive global warming bill last came to the floor in 2005, only 38 senators voted in favor of it. Today, our nation is poised to confront this challenge and once again become an environmental leader in the world.

In remarkable contrast to President Bush – who fiercely defends the status quo and threatened to veto the bill even before he saw the final product – both presidential candidates said they are in favor of addressing the issue now.

It is imperative that we move forward – not just for the sake of our planet, our children and grandchildren, and all of God’s creatures threatened by global warming, but also for the sake of our economic security.

The best hope we have for affordable energy is to pass a bill like the Climate Security Act, which will allow the free market to put a price on carbon and send a signal that it is time to invest in alternative energy and new technology. Continuing to rely on big oil and conventional coal would be the worst scenario for the American people, who are paying more than $4 a gallon at the pump and being held captive by hostile Middle East regimes that have too much control over our energy policy.

What better time to encourage the development of alternative fuels and energy efficient technology than when oil is nearly $140 a barrel?

Silicon Valley leaders have told me that when we enact a strong, federal cap-and-trade law, they anticipate billions of dollars in investment in green technology, which will create millions of “green jobs” here in America. And, if we take those steps now, we will be able to export that technology to other nations.

The Senate debate, however abbreviated, gave us a road map for the future. But until we have a new president who is willing to work with us to confront this challenge, we must continue to push policies forward at the state level.

One of the central fronts in that battle is California’s efforts to obtain a waiver from the Clean Air Act so that we can implement standards to reduce greenhouse gas emissions from vehicles.

California has been granted a waiver from the Clean Air Act more than 50 times by both Republican and Democratic administrations, but President Bush and political operatives at the Environmental Protection Agency for the first time outright denied California’s request for a waiver, overruling the unanimous opinion of EPA’s career scientists and lawyers.

EPA’s decision means that California, and at least 14 other states that adopted California’s standards, cannot act. The states, led by California’s attorney general, are suing EPA, and I will file an amicus brief supporting them in their efforts.

I hope the courts will act quickly to reverse EPA’s outrageous decision so that California can get started on this problem and continue to set an example for the federal government.

Our generation has been handed a tremendous challenge. Legislation to combat global warming will not happen overnight; it took 10 years to pass major Clean Air Act legislation. We started voting on comprehensive global warming legislation in the Senate five years ago. We must get there – scientists have told us clearly that time is not on our side.

We must convince the negative voices that we need to act now to avert the dangers of global warming.

BARBARA BOXER, a Democratic U.S. senator from California, is chairwoman of the Senate environment and public works committee and a sponsor of the Boxer-Lieberman-Warner Climate Security Act. She wrote this article for the Mercury News.

A transit village with apartments, retailers, restaurants and a hotel is rising in Milpitas next to The Great Mall, close to light rail and the under-construction BART station. It’s one of several Silicon Valley projects sprouting up near transit.